The Concept of Non-Contractual Obligations

 
of
 
an independent and comprehensive doctrinal category of „unjustified enrichment‟ 
besides contract and tort law disrupts the integrity of contract law and the division 
of contractual and non-contractual obligations: such a category is as misleading as 
the idea of a „law of fault‟ would be. Furthermore, if the enrichment is seen in itself 
as an event triggering liability, such a category may induce lawyers to overlook 
questions about the possible relations between tort law and enrichment liability 
based on encroachment. 
2. Contractual and non-contractual liability: pre-contractual negligence 
Similarly, the borderline between contract law and tort law may prove difficult to 
draw. Thus, contractual and delictual liability may overlap or compete in cases 
where the breach of contract may also be regarded as a delict and vice versa.
116
This 
problem is evident in legal systems, such as the French, that proceed from the 
assumption that all interests are equally protected under tort law.
117
Hence, every 
breach of contract could be re-interpreted as a delict.
118
Yet most legal systems have 
found some way to preserve the integrity of the core of contract law by treating the 
rules of contract law as some kind of 
leges speciales
that exclude competing claims 
under tort law. 
Secondly, all legal systems face the converse situation where a delict 
115
This principle is normally not disputed; even in Germany, a claim for unjustified enrichment 
presupposes enrichment „auf Kosten (at the expense)‟ of the claimant (cf § 812 (1) BGB). The only 
question today is whether the claim is limited by the claimant‟s actual loss: see 
N Jansen
, 
Binnenmarkt, Privatrecht und europäische Identität (2004) 45 ff with further references to the 
national discussions. 
116
See 
von Bar
(fn 2) vol I, [413] ff.
117
See generally 
von Bar
(fn 2) vol I, [419] ff, [431] ff, with further references. French law is 
therefore based on the principle of 
non-cumul des responsabilités
: there can be no delictual liability 
as far as the rules of contract law are applicable. Similarly, in other legal systems, such as in Greece, 
Denmark and Portugal, it is well established that the mere breach of a contractual duty cannot give 
rise to a claim under tort law. German law, on the other hand, can proceed from the contrary starting 
point that there is a free concurrence of contract and tort, because under German law, purely 
economic losses only exceptionally give rise to a delictual claim. 
118
On the recent French jurisprudence according to which every breach of a contract may be 
regarded as a delict vis-à-vis
 
third parties, see 
J-S Borghetti
, Breach of Contract and Liability to 
Third Parties in French Law: How to Break Deadlock, forthcoming in [2010] Zeitschrift für 
Europäisches Privatrecht (ZEuP). 

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22 
amounts to a breach of contractual duties. This is especially relevant for service 
contracts where the body or the goods of one party are exposed to treatment by the 
other party. Yet it may also be the case under a contract for sale where further 
damage results from the defective goods. Especially in these cases, parties often 
make contractual agreements that also relate to delictual liability. Thus, Roman 
craftsmen working on the equally fragile and precious diatret glasses usually 
insisted on their work being done at the client‟s risk, and this contractual agreement, 
we are told by Ulpian, also excluded the possibility of suing on the basis of a 
delictual